Overshot tool string knuckle joint



Feb. 12, 1952 w. H. DUMBLE 2,585,303

OVERSHOT, TOOL STRING KNUCKLE JOINT Filed Aug. s1, 194e Patented Feb. 12, 1952 UN I T ED STATES PATENI :OFFICE 4OVERSHOT TOOL. STRING .KNUCKLE 4.JQINLI William n. Bumble, Bakersfield, Calif. Application August 31, 1946Seria1-rNn. 69.4,'3578 This invention is a fishing tool apparatus, for use in deep earth holes or wells, of the type shown by Baker Patent No. 1,718,771.

It is an object of this invention to greatly simplify theA liquid circulating, -knuclde joint of the above mentioned patent by wholly eliminating any pin and socket form of positive connection of the tool device to the body of the apparatus. And an Objectis to eliminate any form of guided piston rod feature such as shown by Baker, supra.

Importantly, an object of the invention is to provide a tool carrying section and a hydraulically driven piston which are directly interengageable so that no lateral thrust, spacial cam parts Vare needed. Also a purpose, here, is to provide a piston all of the effort of which is expended in a straight, axial direction onto an immediately adjacent top corner of a head part of 'the tool section and which latter has a fulcrum on which it see-saws under the vertical .presser piston.

Another object is to provide a too'l .section which is so combined with the main Vbody element of the apparatus as to be capable of bodily axial 'shift as distinguished from any form ,of pin, or

ball, and socket hinge which requires much and careful machining.

A further purpose of the invention is to provide a'knuckle, tool joint that is very compact and of particularly short length by reason of elimi nation of piston rods and long cam features. i

Also, it is an aim of the invention to provide a knuckle, tool joint whose parts will telescopcally receive and grapple the upper end of a well hole. Another object is to provide a means for milling off the ragged edge of the sh end if, and when possible, to facilitate 'its entrapment by the knuckle tool section and provide a pulling vmeans therein. In this connection a purpose of 4 the invention is to provide a knuckle, tool joint having means to pack off the intruded fish end when this is practical and desirable.

.The invention resides in certain advancements in the tool, knuckle joint art asset forth in the ensuing disclosure and having, with the above, additional objects and advantages as hereinafter developed, and whose constructions, combinations, Land details of means `and the manner lof operation will be made manifest in the following description of the herewith illustrative embodiment: it being understood that variations may be exercised within the spirit of the invention as it is claimed in conclusion hereof.

Fig. 1 is an elevation of the tool joint; partly ing head of the :section H.

5 Claims. (Cl. '2M-"86) .in axial section. Fig. is a .longitudinal sectQn thereof; the section being tilted. Fig, 3 is an `axial section showing the joint ,parts in fish pulling position. Fig. -4 is `a top ,plan of the tool section head.

lThe knuckle jointas setoutincludes a Vtubular body 2 suitably attachable .to .the l.lower .end `of a pipe string S for circulating and pressure liquid. Projecting from the lower .end -of :said

body is a short, tubular tool Vsection ,Il having a flattened portion l5 ,tilting ina ,comp1ementary slot Ill across the lower -end .of the .body f2; ,the lower end of the tool section .being adapted for attachment of any desired .implement or tool, such as the illustrated .wall hook H.

In order that .the `tool section may have Adesired bodily shift in the body 2 there is no positive pin or ball and socket connection of the tool .section to the body. Instead, the tool section has an enlarged head ll-withan annular, .bottom ledge having a diametrical, fulcruming vedge ft2 herein called the fulcrum. The :ledge hasone, flat, anvil-forming face IIzaat a `right angle from the joint axis to one side -of the head, whilst from the other side of vsaid fulcrum a :relief 4face I2r pitches upward, at a suitable Obliquity, to the relative -(ri ght.hand) ,side of the head which has a conic l:surface |20 so Vthat as the head see-saws on its fulcrum l2 the head .can move toward the body wall. The slot I4 is extended to the lef-t to provide clearance :for the tool section Il in tilting action. The Aconic Vface 12e of the head extends to and merges with Aa high peak 42pof the 'head so that a straight downward pressure on the peak .will see-saw the head and its .body section Il on ,the fulcrum l2.

The head ledge faces |2a and 12T are'engageable `with and supported on an annular, internal shoulder v2s in the lower end of the -bore of the hollow body 2 and bordering `the guiding Slot I4. Fig. 1 shows the anvil face I2a ofthe head rresting in normal, lowering vposition of the joint parts, which is also the ,position vfor an upward jarring function of the body shoulder 2s when this is used as a hammer to jolt the :anvil form- Further, the shoulder takes the .load Vof the section Il .and a sh part F which is vcaught and being pulled from the well hole.

A tubulanfluid.pressure-actuated means, of the general type shown by Baker, supra, to act directly on the head IU of the tilting section l I, is provided and is characterized as a Very short piston I'I, packed and slidably fitted in the bore of the 55 body 2 in a position immediately above the head assessori I2p results in side thrust of immaterial in degree while the head seesaws on its fulcrum on the shoulder 2s. The piston of this embodiment, Fig. 2, comprises an outer tubular cylinder With external packing I8 sealing the body bore and havlng an inner concentric packing I9 sealing an inner, concentric core cylinder formed of two, matched sections 26a-20h having a small, central, axial restrictive orice 2l to control liquid flow down to the hollow section I I.

The core cylinder (20a-20h) is provided with external notches 22 at opposite sides for reception of spring dogs 23, pivoted in the upper end of the cylindric piston I1, which hold the core piston in place while heavy fluid pressure may be set up on the piston assembly to force it straight down on the peak I2p of the stem when this is to be tilted; whereby to push the bottom end of the vwall hook far out from the body to hook onto the fish F as the tool string S is rotated with the object of working the top end of the sh into axial position in the wall hook socket; this being an over-shot form of fishing tool.

The core piston sections are slidable as an assembled unit into the bore of the outer cylinder Il and are normally under expansive pressure of a suitable spring device 24 so that if and when the core piston is upwardly ejected from the outer cylinder the freed core sections will be instantly spread apart as shown in Fig. 3. The dislodgement of the orifice forming core piston will allow a centered sh F to pass through the hollow ksection II and through the piston cylinder I'I.

in the wall of the tubular section II and when a collar C has passed these dogs they will close in under the collar and thus lock the fish F in axial position for pulling from the well hole.

To facilitate the entry of the fish end into the socket of the section II there is xedly mounted against the bottom end of the said section a circular mill 2 6 which will operate to cut oi ragged spurs that may obstruct the entry of the top end of the fish into the said socket. The mill may be clamped in place by the hub of the applied wall hook H.

When the sh has been nally centered in the socket of the said section II the tool string may be lowered to set the slidable core piston 20a-2 0b down on the fish with such pressure as to force the core piston up and out of the outer piston cylinder Il; whereby to permit copious flow of liquid down the sh to aid in breaking it from formation in the well hole.

If desired, the section II may be fastened by one or more shear pins 21, Fig. 1, and likewise the core piston 20a/ 20h may be shear pinned at 28 to the main or carrier piston I1.

What is claimed is:

1. A tubular shell having at its lower end an internal guide, a tool joint member pivotally supported in the shell at a level above said guide and having a stem portion below its pivot axis fitted and swinging to and fro in the guide, the said member projecting down through in the guide Without relative rotation around the axis of the shell, and a hydraulically actuated piston in the shell and operative on said member to tilt it in the guide said member having spaced stop parts at the ends of the guide tc engage the same and prevent axial shift of the axially alined joint member in the guide, and said member having an overshot grab sleeve screwed on its lower end.

2. 'l'he combination set out in claim l, and including an internal end mill bit interlocked with the lower end of said member and being clamped in place by said sleeve.

3. A tool string knuckle joint having a stem member with a head having a topmost abutment corner off to one side of its longitudinal axis, a shell having a pivot portion on which said stem is tiltably supported and said topmost corner being above the horizontal plane of the axis on which said stern tilts, and a piston operative in the shell and having an abutment face engageable with said topmost corner and operative to depress it in a generally vertical arcuate path about said axis.

4. ln a knuckle joint for a well pipe tool string; a tubular body attachable at its top to a part of said string, a hollow section pivotally supported in and by said body and adapted for attachment of a fishing tool, a lluid presser piston shiftable axially in the body for tilting the said section and including a dislodgeable core to permit descent of said section and said body in overshot position along a iish part; the core consisting of a, set of matched, longitudinal members forming a restricted-low passageway.

5. In a knuckle joint for a well pipe tool string: a tubular body attachable to a part of the said string, a hollow section pivotally supported in and by said body and adapted for attachment of a iishing tool, a fluid presser piston shiftable axially in said body for tilting said section and having a dislodgeable core; the said piston having a bore in which the core is fitted, and packing lining the .bore to seal onto a complementary sh part onto which the piston is functionally telescoped.

WILLIAM H. DUMBLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,594,668 Gates et al- Aug. 3, 1926 1,696,378 Brauer Dec. 25, 1928 1,718,771 Baker June 25, 1929 1,738,819 Cormier Dec. 10, 1929 1,800,490 Young Apr. 14, 1931 2,026,295 Baker Dec. 31, 1935 

